The state of the art is indicated by the following set of references. Gottschalk U.S. Pat. No. 5,495,738; Gottschalk, et al U.S. Pat. No. 5,445,003; Bone U.S. Pat. No. 5,493,761; Winkens U.S. Pat. No. 5,138,859; Betsrein U.S. Pat. No. 4,561,276; Ostertag U.S. Pat. No. 4,947,668.
It is well known in the art to have various machines and methods to strengthen and finish metal work pieces such as camshafts and crank shafts, for internal combustion engines. In many modern day automobiles engines have been downsized for installation into smaller vehicles. Accordingly, automotive vehicles and their components are being downsized to reduce weight and improve fuel efficiency, hence, smaller engines and crank shafts are needed. Therefore, there is a need to improve the fatigue strength and durability of the smaller, downsized crank shafts. This improved fatigue strength and durability is accomplished by deep rolling of fillets and other circular joint areas upon the crankshaft. The fatigue strength and durability of crank pins and main bearing journals can be significantly increased by deep rolling compressive stresses into the middle of the annular fillets between the pin journals and adjacent counter weights or balancing webs.
During the deep rolling process, the industry has known for numerous years to provide a full flooding process necessary to lubricate and/or cool the work tools and work piece while the work tools are engaging the work piece. A more recent process of lubricating and/or cooling includes a limited coolant supply in the form of a mist. Both of these cooling/lubricating methods tend to cause shavings from the work piece and other debris or foreign matter in the work area to adhere to the work piece and work tool mechanism.
The adherence of debris to the work tool and work pieces creates many problems for the industry. First, there is considerable wear and tear of the tool mechanism, effectively shortening tool life. Second, to increase the life and performance of the work tools, many man-hours are required to disassemble the work tools for cleaning and to reassemble for subsequent use of the cleaned tools. This greatly affects productivity, which is diminished because the work tools cannot be used in the deep rolling process during cleaning. Furthermore, the complexity of disassembling the work tool for cleaning and replacing any worn parts is time consuming and also affects the productivity and life expectancy of the tools. Third, debris collecting on the work area may work its way between the work tool and work piece during the deep rolling process and cause compressive stresses to be misaligned, effectively negating the purpose of the deep rolling process and negatively affecting the life of the crank shaft or other work piece being rolled. Fourth, there is the increased cost of the deep rolling process by having to replace the work rolls more often due to the negative effect of all the shavings and pieces.
There also have been problems with prior art deep rolling machines with regard to the complexity of assembling and disassembling the upper and lower tools to accommodate changes of worn out parts or cleaning of the tools themselves. The amount of time necessary to assemble and disassemble the tools, along with the down time of the line on which the tool is operating all adversely affect the productivity of the tool and the assembly line process. Furthermore, in many prior art deep rolling machines, disassembling of the tool is necessary to replace worn out roller cages, held in place by cage retainers. The roller cages in the prior art machines are set into a predetermined location with relation to the back up roller and work rolls. Once they are worn out they become ineffective and have to be replaced. This entire process is costly in the amount of time necessary to replace, as well as the cost of the parts. Therefore, there is a need in the art for adjustable roller cages that work in conjunction with cage retainers or even without the cage retainers. There also is a need in the art for adjustable split cages for use in conjunction with cage retainers or on their own within a tool structure. Also there is a need in the art for an easier to disassemble and assemble upper and lower tool, decreasing down time and maintenance, and thus increasing productivity of the deep rolling mechanism in the manufacturing environment.